The measurement of blood glucose concentration is important for the prevention and control of many chronic and potentially fatal medical conditions such as cardiovascular diseases and diabetes. In order to measure blood glucose level, a user has to use a glucose concentration measurement system. These systems can broadly be classified into two types—invasive type and non-invasive type.
Many of the traditional glucose concentration measurement systems are invasive systems. To measure glucose concentration, a user has to prick the skin (e.g., on a fingertip) to draw a small sample of blood. The blood is transferred to a test strip, which is then inserted into to the system. The system analyzes the blood sample on the test strip to determine the blood glucose level. A reading of the glucose level is displayed to the user on a display means (e.g., screen) of the system. These invasive systems are generally not user-friendly, bulky, and expensive.
Because of the above problems, non-invasive glucose concentration measurement systems have been heavily researched and developed in the last few decades. These non-invasive systems measure glucose level indirectly based on different physical principles, without requiring the creation of a wound to obtain blood sample. Examples of these systems include polarimetry-based systems, impedance-based systems, electrochemistry-based systems, microwave-technique-based systems, and optical-based systems.
In spite of these recent advancements, significant challenges remain for the development of glucose concentration measurement systems. These challenges include: weak detection signal due to relatively low concentration of glucose in blood; detection is susceptible to influence by background tissues (e.g., skin, muscle, etc.); blood volume change caused by cardiac impulse may lead to instability for light intensity based spectrum analysis; optical-based detection devices are generally bulky and expensive. Thus, there remains a need for the development of a more reliable, efficient, and accurate means and method for measuring blood glucose concentration.